In a related art, for example, Patent Document 1 discloses a vapor compression refrigeration cycle device that is applied to an air conditioner. The refrigeration cycle device can be configured to switch between an operation mode (e.g., air heating mode) of heating a space to be air-conditioned by heating air (fluid to be heat-exchanged) to be blown into the space to be air-conditioned, and another operation mode (e.g., air cooling mode) of cooling the space to be air-conditioned by cooling the air.
The refrigeration cycle device disclosed in Patent Document 1 further includes an accumulator (gas-liquid separator) that separates a low-pressure refrigerant into gas and liquid phases, and stores therein an excessive liquid-phase refrigerant. Even when switching to either of the operation modes, the low-pressure gas-phase refrigerant separated by the accumulator is drawn into a compressor.